The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Vehicle powertrains typically include a prime mover, such as an internal combustions engine, that drives a transmission through a coupling device. In some cases, the transmission includes an automatic transmission that is driven by the prime mover through a torque converter. The transmission multiplies the engine drive torque by a desired gear ratio and transfers the multiplied drive torque to a driveline to propel the vehicle.
A control module regulates operation of the transmission based upon vehicle operating parameters including, but not limited to, vehicle speed and throttle position. More specifically, the control module includes predetermined shift lines that are used to command upshift and downshifts.
In some instances, the vehicle is rapidly decelerated, for example, to avoid a collision or to otherwise come to a rapid stop. As the vehicle decelerates, several events can simultaneously occur including, but not limited to, suspension movement, axle wind-up and a transmission downshift. Under certain conditions, a transmission downshift can result in undesired driveline disturbances in the form of noise (e.g., an audible clunk) and/or driveline oscillations.